Why I am not getting any result from rawQuery method in android

Why I am not getting any result from rawQuery method in android - java

I am doing a simple SQlite Apps where I want to save group name in a table and show it on a listview as soon as user click on the add button.
Can any body help me why I am not getting null value from rawQuery result?
public class AddData {
public static final String TAG = DbHelper.class.getSimpleName();
public static final String DB_NAME = "Grup.db";
public static final int DB_VERSION = 1;
public static final String TABLE = "Grups";
public static final String C_ID = BaseColumns._ID;
public static final String C_CREATED_AT = "easy_ass_created_At";
public static final String C_NAME = "name";
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
public class DbHelper extends SQLiteOpenHelper {
// public static final String TAG = DbHelper.class.getSimpleName();
// public static final String DB_NAME = "Grup.db";
// public static final int DB_VERSION = 1;
// public static final String TABLE = "Grups";
// public static final String C_ID = BaseColumns._ID;
// public static final String C_CREATED_AT = "easy_ass_created_At";
// public static final String C_NAME = "name";
public DbHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String sql = ("create table " + TABLE + " ( " + C_ID
+ " integer primary key autoincrement, " + C_NAME
+ " text not null" + ");");
db.execSQL(sql);
Log.d(TAG, "OnCreate sql" + sql);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + TABLE);
this.onCreate(db);
Log.d("TAG", "********On Upgrate Drop Table*****");
}
}
public AddData(Context context) {
ourContext = context;
}
public AddData open() throws SQLException {
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getReadableDatabase();
return this;
}
public void close() {
ourHelper.close();
}
public long createEntry(String name) {
ContentValues cv = new ContentValues();
cv.put(C_NAME, name);
return ourDatabase.insert(TABLE, null, cv);
}
public String getData() {
String[] columns = new String[] { C_ID, C_NAME };
Cursor c = ourDatabase.query(TABLE, columns, null, null, null, null,
null);
String result = "";
// int iRow=c.getColumnIndex(C_ID);
int iName = c.getColumnIndex(C_NAME);
// for(c.moveToFirst();!c.isAfterLast();c.moveToLast()){
for (boolean hasItem = c.moveToFirst(); hasItem; hasItem = c
.moveToNext()) {
result = result + " " + c.getString(iName) + "\n";
c.moveToNext();
}
c.close();
return result;
}
public ArrayList<String> fatchData() {
ArrayList<String> results = new ArrayList<String>();
try {
Cursor c = ourDatabase.rawQuery("SELECT * from Grups;", null);
if (c != null) {
if (c.moveToFirst()) {
do {
String firstName = c.getString(c.getColumnIndex("name"));
results.add("Project: " + firstName);
} while (c.moveToNext());
}
}
} catch (Exception e) {
e.printStackTrace();
}finally {
if (ourDatabase != null)
ourDatabase.execSQL("DELETE FROM Grups");
ourDatabase.close();
}
return results;
}
}

Try removing c.close() and use startManagingCursor(c) (after creating the cursor) in your getData() method

Related

Creating SQLite database for Live magnetic sensor data

I am new in Android platform. I want to record the live magnetic sensor data directly to sQLite database in storage. I wrote code to get magnetic data but i am not able to create the database. I have pasted code below. Any help would be great.
Thank you in advance.
// code for Database Helper
public class DBHelper extends SQLiteOpenHelper{
private static final String DB_NAME = "Mag_Positioning.db";
private static final int DB_VERSION = 1;
private static final String COL_ID = "ID";
private static final String COL_XAXIS = "X-AXIS";
private static final String TABLE_NAME = "MAP_COORDINATES";
private static final String COL_YAXIS = "Y-AXIS";
private static final String COL_ZAXIS = "Z-AXIS";
public DBHelper(Context context){
super(context, DB_NAME, null, DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + TABLE_NAME + "(" + COL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COL_XAXIS + " INTEGER," + COL_YAXIS + " INTEGER," + COL_ZAXIS + " INTEGER" + " )";
db.execSQL(createTable);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public void insert(Integer xaxis, Integer yaxis, Integer zaxis){
SQLiteDatabase db = this.getWritableDatabase();
}
}
// code for getting magnetic sensor data
// Its just fragment of code
public class MainActivity extends AppCompatActivity implements SensorEventListener {
Sensor magnetometer;
SensorManager sm;
TextView magnetismx;
TextView magnetismy;
TextView magnetismz;
DBHelper dbHelper;
public float a;
public float b;
public float c;
boolean recording = false;
boolean stoprecord = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper = new DBHelper(this);
// I have declared some button here...
#Override
public void onSensorChanged(SensorEvent event) {
Sensor sensor = event.sensor;
a = event.values[0];
b = event.values[1];
c = event.values[2];
if (sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) {
magnetismx.setText(Float.toString(event.values[0]));
magnetismy.setText(Float.toString(event.values[1]));
magnetismz.setText(Float.toString(event.values[2]));
if (!recording) {
return;
}
if(stoprecord){
return;
}
}
try {
writeToCsv(Float.toString(a), Float.toString(b), Float.toString(c));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ps: The code for database is not working too.. The table is not created.

I sorted out the problem myself. There was some problem in database class. I have used the below code for database helper class.
ublic class DBHelper extends SQLiteOpenHelper {
private static final String DB_NAME = "Mag_Positioning.db";
private static final int DB_VERSION = 1;
//Table for measurement
private static final String ID = "id";
private static final String MAP_ID = "Mapid";
private static final String COLXAXIS = "X_AXIS";
private static final String TABLENAME = "Fingerprint";
private static final String COLYAXIS = "Y_AXIS";
private static final String COLZAXIS = "Z_AXIS";
private static final String MAPX = "X_CORD";
private static final String MAPY = "Y_CORD";
private static final String DIFF = "Diff";
private static final String FINAL = "FINAL";
private static final String KEY_FINGERPRINT_ID = "id";
private static final String KEY_MAP_NAME = "map_name";
private static final String KEY_POSITION_X = "position_x";
private static final String KEY_POSITION_Y = "position_y";
private static DBHelper mInstance;
public DBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
public static DBHelper getInstance() {
if (mInstance == null) {
synchronized (DBHelper.class) {
if (mInstance == null) {
mInstance = new DBHelper(BaseApp.getApp());
}
}
}
return mInstance;
}
#Override
public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + TABLENAME + "("
+ ID + " INTEGER PRIMARY KEY,"
+ MAP_ID + " INTEGER ," +
MAPX + " INTEGER, " +
MAPY + " INTEGER, " +
COLXAXIS + " REAL, " +
COLYAXIS + " REAL, " +
COLZAXIS + " REAL, " +
FINAL + " REAL )";
db.execSQL(createTable);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLENAME);
onCreate(db);
}
public void insert(int a, int b, int c, float x, float y, float z, float d) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentvalues = new ContentValues();
contentvalues.put("Mapid", a);
contentvalues.put("X_CORD", b);
contentvalues.put("Y_CORD", c);
contentvalues.put("X_AXIS", x);
contentvalues.put("Y_AXIS", y);
contentvalues.put("Z_AXIS", z);
contentvalues.put("FINAL", d);
db.insert("Fingerprint", null, contentvalues);
db.close();
}
public void deleteAllFingerprints() {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLENAME, null, null); // delete all fingerprints
db.close();
}
public Cursor getAllData() {
SQLiteDatabase db = this.getWritableDatabase();
Cursor cur = db.rawQuery("select * from " + TABLENAME, null);
return cur;
}
}

NullPointerException at this.getReadableDatabase();

Heyhey :)
I looked at several Questions to the same topic, but I found no solution to my problem.
A NullPointerException at this.getReadableDatabase(); appears...
Here's my Code:
public class DatabaseHandler extends SQLiteOpenHelper {
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "TODO_APP";
/*--------------------------- TABLE ITEMS START ---------------------------*/
private static final String TABLE_ITEMS = "items";
private static String KEY_ID_ITEMS = "id_items";
private static final String KEY_CATEGORY_ITEMS = "category";
private static final String KEY_DATETIME_ITEMS = "datetime";
private static String KEY_NAME_ITEMS = "name";
private static final String KEY_DESCRIPTION_ITEMS = "description";
private static final String KEY_ALARM_ITEMS = "alarm";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
// create table ITEMS
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + "("
+ KEY_ID_ITEMS + " INTEGER PRIMARY KEY," + KEY_CATEGORY_ITEMS
+ " INTEGER," + KEY_DATETIME_ITEMS
+ " TIMESTAMP DEFAULT CURRENT_TIMESTAMP," + KEY_NAME_ITEMS
+ " TEXT," + KEY_DESCRIPTION_ITEMS + " TEXT," + KEY_ALARM_ITEMS
+ " INTEGER" + ");";
db.execSQL(CREATE_ITEMS_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_ITEMS);
// Create tables again
this.onCreate(db);
}
public void addItem(DB_Item item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_CATEGORY_ITEMS, item.getCategory());
values.put(KEY_NAME_ITEMS, item.getName());
values.put(KEY_DESCRIPTION_ITEMS, item.getDescription());
values.put(KEY_ALARM_ITEMS, item.getAlarm());
// Inserting Row
db.insert(TABLE_ITEMS, null, values);
db.close(); // Closing database connection
}
public DB_Item getItem(String name) {
//!!!!! Here is one problem !!!!!
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_ITEMS, new String[] { KEY_ID_ITEMS,
KEY_CATEGORY_ITEMS, KEY_DATETIME_ITEMS, KEY_NAME_ITEMS,
KEY_DESCRIPTION_ITEMS, KEY_ALARM_ITEMS },
KEY_NAME_ITEMS = " = ?", new String[] { String.valueOf(name) },
null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
// DB_Item (int category, String name, String description, int
// alarm)
DB_Item item = new DB_Item(cursor.getInt(1), cursor.getString(3),
cursor.getString(4), cursor.getInt(5));
return item;
}
public List<DB_Item> getAllItems() {
List<DB_Item> itemList = new ArrayList<DB_Item>();
// SELECT ALL
String selectQuery = "SELECT * FROM " + TABLE_ITEMS;
//!!!!!!!!!! here is the other Problem
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
// go through all rows and then adding to list
if (cursor.moveToFirst()) {
do {
DB_Item item = new DB_Item();
item.setCategory(Integer.parseInt(cursor.getString(0)));
// TODO
// adding to list
itemList.add(item);
} while (cursor.moveToNext());
}
return itemList;
}
[and so on, didn't copy the whole code]
Hope you can help me...
The error appears definitely at SQLiteDatabase db = this.getReadableDatabase();
Output:
09-03 08:34:17.863: E/AndroidRuntime(7074): java.lang.RuntimeException: Unable to start activity ComponentInfo{todo.todo_list/todo.view.StartApp}: java.lang.NullPointerException
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.database.DatabaseHandler.getAllItems(DatabaseHandler.java:144)
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.helper.SortItems.sortItemsCategory(SortItems.java:16)
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.view.StartApp.onCreate(StartApp.java:36)

chnage you class to something like this:
package com.mhp.example;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBAdapter {
/*--------------------------- TABLE ITEMS START ---------------------------*/
private static final String TABLE_ITEMS = "items";
private static String KEY_ID_ITEMS = "id_items";
private static final String KEY_CATEGORY_ITEMS = "category";
private static final String KEY_DATETIME_ITEMS = "datetime";
private static String KEY_NAME_ITEMS = "name";
private static final String KEY_DESCRIPTION_ITEMS = "description";
private static final String KEY_ALARM_ITEMS = "alarm";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "dbname";
private static final int DATABASE_VERSION = 1;
tring CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + "("
+ KEY_ID_ITEMS + " INTEGER PRIMARY KEY," + KEY_CATEGORY_ITEMS
+ " INTEGER," + KEY_DATETIME_ITEMS
+ " TIMESTAMP DEFAULT CURRENT_TIMESTAMP," + KEY_NAME_ITEMS
+ " TEXT," + KEY_DESCRIPTION_ITEMS + " TEXT," + KEY_ALARM_ITEMS
+ " INTEGER" + ");";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db)
{
try {
db.execSQL(CREATE_ITEMS_TABLE);
} catch (SQLException e) {
e.printStackTrace();
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
}
//---opens the database---
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close()
{
DBHelper.close();
}
public void addItem(DB_Item item) {
ContentValues values = new ContentValues();
values.put(KEY_CATEGORY_ITEMS, item.getCategory());
values.put(KEY_NAME_ITEMS, item.getName());
values.put(KEY_DESCRIPTION_ITEMS, item.getDescription());
values.put(KEY_ALARM_ITEMS, item.getAlarm());
// Inserting Row
db.insert(TABLE_ITEMS, null, values);
}
public DB_Item getItem(String name) {
Cursor cursor = db.query(TABLE_ITEMS, new String[] { KEY_ID_ITEMS,
KEY_CATEGORY_ITEMS, KEY_DATETIME_ITEMS, KEY_NAME_ITEMS,
KEY_DESCRIPTION_ITEMS, KEY_ALARM_ITEMS },
KEY_NAME_ITEMS = " = ?", new String[] { String.valueOf(name) },
null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
// DB_Item (int category, String name, String description, int
// alarm)
DB_Item item = new DB_Item(cursor.getInt(1), cursor.getString(3),
cursor.getString(4), cursor.getInt(5));
return item;
}
public List<DB_Item> getAllItems() {
List<DB_Item> itemList = new ArrayList<DB_Item>();
// SELECT ALL
String selectQuery = "SELECT * FROM " + TABLE_ITEMS;
Cursor cursor = db.rawQuery(selectQuery, null);
// go through all rows and then adding to list
if (cursor.moveToFirst()) {
do {
DB_Item item = new DB_Item();
item.setCategory(Integer.parseInt(cursor.getString(0)));
// TODO
// adding to list
itemList.add(item);
} while (cursor.moveToNext());
}
return itemList;
}
}
NOTE: when you create object from DBAdapter,you should open() db and after your work close() it.
DBAdapter db = new DBAdapter(contex);
db.open();
//do you work
db.close();

Just use getReadableDatabase() without this.

SQLite database works on emulator but not on device

I am using sqlite database in my android application. I am pre-creating the database in the databases folder in android. The databases is created and works fine in the emulator but when I run the same code in my phone I get errors.
Here is the code on how I pre-create the database in the databases folder.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SavingData.mainActivity = this;
try {
String destPath = "/data/data/" + getPackageName() + "/databases";
File f = new File(destPath);
if (!f.exists()) {
f.mkdirs();
f.createNewFile();
// ---copy the db from the assets folder into
// the databases folder---
CopyDB(getBaseContext().getAssets().open("exercisedatedb"),
new FileOutputStream(destPath + "/ExerciseDateDB"));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void CopyDB(InputStream inputStream, OutputStream outputStream)
throws IOException {
// ---copy 1K bytes at a time---
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) > 0) {
outputStream.write(buffer, 0, length);
}
inputStream.close();
outputStream.close();
}
}
Here is the errors I get:
04-01 12:51:12.503: E/SQLiteLog(26823): (1) no such column: date
04-01 12:51:12.503: D/AndroidRuntime(26823): Shutting down VM
04-01 12:51:12.503: W/dalvikvm(26823): threadid=1: thread exiting with uncaught exception (group=0x40f722a0)
04-01 12:51:12.508: E/AndroidRuntime(26823): FATAL EXCEPTION: main
04-01 12:51:12.508: E/AndroidRuntime(26823): android.database.sqlite.SQLiteException: no such column: date (code 1): , while compiling: SELECT id, date FROM dates
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1013)
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:624)
Here is how I insert data to database:
public void insertDate(String date) {
// TODO Auto-generated method stub
db.open();
long id = db.insertDate(date);
db.close();
}
Here is my DBAdapter class:
public class DBAdapter {
static final String KEY_ROWID = "id";
static final String KEY_DATE = "date";
static final String TAG = "DBAdapter";
static final String DATABASE_NAME = "ExerciseDateDB";
static final String DATABASE_TABLE = "dates";
static final int DATABASE_VERSION = 1;
static final String DATABASE_CREATE = "create table dates (id integer primary key autoincrement, "
+ "date text not null);";
final Context context;
DatabaseHelper DBHelper;
SQLiteDatabase db;
public DBAdapter(Context ctx) {
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(DATABASE_CREATE);
} catch (SQLException e) {
e.printStackTrace();
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
}
// ---opens the database---
public DBAdapter open() throws SQLException {
db = DBHelper.getWritableDatabase();
return this;
}
// ---closes the database---
public void close() {
DBHelper.close();
}
// ---insert a Date into the database---
public long insertDate(String date) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_DATE, date);
return db.insert(DATABASE_TABLE, null, initialValues);
}
// ---deletes a particular date---
public boolean deleteDate(long rowId) {
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
// ---retrieves all the score---
public Cursor getAllDate() {
return db.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_DATE}, null, null, null, null, null);
}
// ---retrieves a particular score---
public Cursor getDate(long rowId) throws SQLException {
Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] {
KEY_ROWID, KEY_DATE}, KEY_ROWID + "= " + rowId + "",
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
// ---updates a score---
public boolean updateDate(long rowId, String date) {
ContentValues args = new ContentValues();
args.put(KEY_DATE, date);
return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
}

This is my database solution. It is all contained in one class.
Too call it the syntax is...
DatabaseManager mDatabase = DatabaseManager.getInstance();
public class DatabaseManager {
private static DatabaseManager instance;
private final String DB_NAME = "singoff_database";
private final int DB_VERSION = 1;
private final String GAME_TABLE_NAME = "game_table";
private final String GAME_ID = "gameid";
private final String GAME_OPPONENT_ID = "opponent";
private final String GAME_TRACK = "track";
private final String GAME_FILE_PATH = "filepath";
private final String GAME_PICTURE = "picture";
private final String GAME_GUESSES = "guesses";
private final String GAME_DATE = "date";
private SQLiteDatabase mDb;
private Context context;
private DatabaseManager(Context context) {
this.context = context;
//create new or open database
DatabaseHelper helper = new DatabaseHelper(context);
this.mDb = helper.getWritableDatabase();
}
public synchronized static DatabaseManager getInstance() {
if (instance == null) {
Context context = Main.getInstance();
instance = new DatabaseManager(context);
}
return instance;
}
//__________________________________________________________________________________________//
//GAME LIST HANDLING STATEMENTS
public synchronized void addGame(String gID, String oID, String track,
String path, byte[] thumb, String datetime) {
ContentValues values = new ContentValues();
values.put(GAME_ID, gID);
values.put(GAME_OPPONENT_ID, oID);
values.put(GAME_TRACK, track);
values.put(GAME_FILE_PATH, path);
values.put(GAME_PICTURE, thumb);
values.put(GAME_DATE, datetime);
mDb.insert(GAME_TABLE_NAME, null, values);
}
public synchronized List<File> getGames() {
List<File> games = new ArrayList<File>();
Cursor cursor;
cursor = mDb.query(
GAME_TABLE_NAME,
new String[]{GAME_FILE_PATH},
null, null, null, null, null);
cursor.moveToFirst();
if (!cursor.isAfterLast()) {
do {
File file = new File(cursor.getString(0));
games.add(file);
} while (cursor.moveToNext());
}
cursor.close();
return games;
}
public synchronized Game getGame(String filepath) {
Cursor cursor;
//Game game = null;
Bitmap picture = null;
byte[] blob;
cursor = mDb.query(
GAME_TABLE_NAME,
new String[]{
GAME_OPPONENT_ID,
GAME_FILE_PATH,
GAME_PICTURE,
GAME_DATE},
GAME_FILE_PATH + "=?",
new String[]{filepath},
null, null, null);
if (cursor.moveToNext()) {
blob = cursor.getBlob(2);
if (blob != null) {
picture = BitmapFactory.decodeByteArray(blob, 0, blob.length);
}
//game = new Game(mContext, new File(filepath), cursor.getString(0), picture);
}
return null;
}
public void updateGame(String filepath, gameColumn col,
Object object) {
ContentValues values = new ContentValues();
switch (col) {
case GAME_PICTURE:
Bitmap picture = (Bitmap) object;
ByteArrayOutputStream out = new ByteArrayOutputStream();
picture.compress(Bitmap.CompressFormat.PNG, 100, out);
values.put(GAME_PICTURE, out.toByteArray());
break;
default:
return;
}
mDb.update(GAME_TABLE_NAME, values, GAME_FILE_PATH + "=?", new String[]{filepath});
}
public synchronized void removeGame(String filepath) {
mDb.delete(GAME_TABLE_NAME, GAME_FILE_PATH + "=?", new String[]{filepath});
}
public enum gameColumn {
GAME_TABLE_NAME, GAME_OPPONENT_ID, GAME_FILE_PATH,
GAME_PICTURE, GAME_DATE
}
//__________________________________________________________________________________________//
//--------------------------------------------------------------------------------------------------
private class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String createGameTableQuery = " CREATE TABLE IF NOT EXISTS "
+ GAME_TABLE_NAME + " ("
+ GAME_ID + " INTEGER, "
+ GAME_OPPONENT_ID + " VARCHAR(20), "
+ GAME_TRACK + " VARCHAR(30), "
+ GAME_FILE_PATH + " VARCHAR(50), "
+ GAME_PICTURE + " BLOB, "
+ GAME_GUESSES + " VARCHAR, "
+ GAME_DATE + " VARCHAR(50)"
+ ");";
//create game table
db.execSQL(createGameTableQuery);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
//TODO
}
}
}

Create a Database Object :
public class Database extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "Exampe.db";
private static final int DATABASE_VERSION = 1;
public static final String ID = "_id";
public static final String NAME = "name";
public static final String UUID = "uuid";
public static final String TABLE_NAME = "Example Something";
private static final String DATABASE_CREATE = "create table "
+ TABLE_NAME + "( " + ID
+ " integer primary key autoincrement, " + NAME
+ " text not null, " + UUID
+ " text not null);";
public Database(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(Database.class.getName(), "Upgrading database from version " + oldVersion + "to " + newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
}
}
Now where you call it
private SQLiteDatabase database;
private Database dbHelper;
private String[] allColumns = { Database.ID, Database.NAME};
public String ExampleSaveName(String name) {
database = dbHelper.getReadableDatabase();
ContentValues values = new ContentValues();
values.put("name", name);
values.put("uuid", uuid);
long insertId = database.insert(Database.TABLE_NAME, null, values);
Cursor cursor = database.query(Database.TABLE_NAME, allColumns, Database.ID + " = " + insertId, null,null, null, null);
cursor.moveToFirst();
return cursorToName(cursor);
}
}

The problem was solved by uninstalling the application from my device.

take all the values from database and store it in a string array

I have made a vegetable class where i will take all the data from database class and i need to store data in a string array.
Say i have items onion,potato with there price 50,80 in database.
now I need to take those values from database and store in my main class as
String items[] = {"onion","potato"};
String price[] = {"50","80"};
My main class is as follows:
package com.ku.bazzar;
public class VegetableActivity extends Activity {
//String items[];
//String price[];
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.vegetables_info);
I tried something like below:
Vegetablesdatabase info = new Vegetablesdatabase(this);
info.open();
items[] = { info.getvegetable();}
price[]= { info.getprice();}
info.close();
I know this is wrong:
items[] = { info.getvegetable();}
price[]= { info.getprice();}
So anyone can please teach me to make string array of the items and price and also create a method getvegetable() and getprice() in my vegetabledatabase file?
I have made a database class as follows
package com.ku.bazzar;
public class Vegetablesdatabase {
public static final String KEY_ROWID = "_id";
public static final String KEY_VEGETABLES = "vegetables";
public static final String KEY_PRICE = "price";
private static final String DATABASE_NAME="ITEM_VEGETABLES";
private static final String DATABASE_TABLE="VEGETABLES";
private static final int DATABASE_VERSION= 1;
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourdatabase;
private static class DbHelper extends SQLiteOpenHelper{
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL( "CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_VEGETABLES + " TEXT NOT NULL, " +
KEY_PRICE + " TEXT NOT NULL);"
);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
public Vegetablesdatabase(Context c){
ourContext = c;
}
public Vegetablesdatabase open() throws SQLException{
ourHelper = new DbHelper(ourContext);
ourdatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}
public long createEntry(String vegetables, String price) {
ContentValues cv = new ContentValues();
cv.put(KEY_VEGETABLES, vegetables);
cv.put(KEY_PRICE, price);
return ourdatabase.insert(DATABASE_TABLE, null, cv);
}
public String getvegetablename(long l)throws SQLException {
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID,KEY_VEGETABLES,KEY_PRICE};
Cursor c= ourdatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "=" + l,null, null, null, null);
if(c!= null){
c.moveToFirst();
String name = c.getString(1);
return name;
}
return null;
}
public String getvegetableprice(long l)throws SQLException {
String[] columns = new String[]{ KEY_ROWID,KEY_VEGETABLES,KEY_PRICE};
Cursor c= ourdatabase.query(DATABASE_TABLE, columns, KEY_ROWID + "=" + l,null, null, null, null);
if(c!= null){
c.moveToFirst();
String name = c.getString(2);
return name;
}
return null;
}
public void updateentry(long lRow, String vegename, String vegeprice) throws SQLException {
// TODO Auto-generated method stub
ContentValues cvupdate = new ContentValues();
cvupdate.put(KEY_VEGETABLES, vegename);
cvupdate.put(KEY_PRICE, vegeprice);
ourdatabase.update(DATABASE_TABLE, cvupdate, KEY_ROWID + "=" + lRow, null);
}
public String getData() {
String [] columns = new String[]{ KEY_ROWID,KEY_VEGETABLES,KEY_PRICE};
Cursor C =ourdatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";
int iRow = C.getColumnIndex(KEY_ROWID);
int ivegetable = C.getColumnIndex(KEY_VEGETABLES);
int iprice = C.getColumnIndex(KEY_PRICE);
for(C.moveToFirst(); !C.isAfterLast(); C.moveToNext()){
result = result + C.getString(iRow) + " " + C.getString(ivegetable) + " " + C.getString(iprice) + "\n";
}
return result;
}
public void deleteEntry(long lRow1) throws SQLException {
// TODO Auto-generated method stub
ourdatabase.delete(DATABASE_TABLE, KEY_ROWID + "=" + lRow1, null);
}
}

You can use the answer provides by octopus or by passing the id to it like
for(int i=0;i<strArray.length;i++){
strArray[i] = info.getvegetable(i);
}
Or you can alter the method so that it returns a string array like below
public String[] getvegetablenames()throws SQLException {
// TODO Auto-generated method stub
String[] columns = new String[]{ KEY_ROWID,KEY_VEGETABLES,KEY_PRICE};
Cursor c= ourdatabase.query(DATABASE_TABLE, columns, null,null, null, null, null);
int i=0;
String[] values=new String[c.getCount()];
c.moveToFirst();
do{
values[i] = c.getString(1);
i++;
}while(c.moveToNext());
return values;
}
The above code may have errors but it is enough for you to get started

String array can be initialized directly with values during declaration. but, when you want to initialize the values by invoking a method, this should be followed
String[] strArray = new String[5]; //Ex: 5 is the size of the array
Vegetablesdatabase info = new Vegetablesdatabase(this);
for(int i=0;i<strArray.length;i++){
strArray[i] = info.getvegetable();
}
//strArray is filled with values after the loop
Please note that info.getvegetable() should return a String literal. if you don't want a fixed size collection, go for a list implementation.
You have to go for ArrayList since you don't have the size needed during initialization
public ArrayList<String> getallvegetable() {
String [] columns = new String[]{KEY_VEGETABLES};
Cursor C =ourdatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
ArrayList<String> result = new ArrayList<String>();
int ivegetable = C.getColumnIndex(KEY_VEGETABLES);
int iprice = C.getColumnIndex(KEY_PRICE);
for(C.moveToFirst(); !C.isAfterLast(); C.moveToNext()){
result.add(C.getString(ivegetable));
}
return result;
}
Hope you understand now!

Access SQLiteOpenHelper onCreate Method from wrapping class

Right now i am calling an insertSomeContacts() function in the onCreate method of the MainActivity which obviously adds the given contacts every time the app is restarted (including screen roation)...since my SQLiteOpenHelper Sub-Class is part of my ContactsDBAdapter Class (which carries the insertSomeContacts() method) - how do i get this function to execute in the SQLiteOpenHelper onCreate so that it only executes once at creation of the database?
Really having problems understanding the scope of this and passing that scope around properly.
MainActivity.java:
public class MainActivity extends Activity {
Intent intent;
private ContactsDBAdapter dbHelper;
private SimpleCursorAdapter dataAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper = new ContactsDBAdapter(this);
dbHelper.open();
//dbHelper.deleteAll();
//dbHelper.insertSomeContacts();
displayListView();
}
private void displayListView(){
Cursor cursor = dbHelper.getAll();
String[] fromColumns = new String[]{
ContactsDBAdapter.COLUMN_TYPE,
ContactsDBAdapter.COLUMN_CLTYP,
ContactsDBAdapter.COLUMN_NAME,
ContactsDBAdapter.COLUMN_VNAME
};
int[] toViews = new int[]{
R.id.contactType,
R.id.contactCltype,
R.id.contactName,
R.id.contactVname
};
dataAdapter = new SimpleCursorAdapter(this, R.layout.contact_entry, cursor, fromColumns, toViews, 0);
ListView listview = (ListView) findViewById(R.id.list);
listview.setAdapter(dataAdapter);
}
ContactsDBAdapter.java:
public class ContactsDBAdapter{
public static final String COLUMN_ID = "_id";
public static final String COLUMN_TYPE = "type";
public static final String COLUMN_CLTYP = "cltyp";
public static final String COLUMN_MDT = "mdt";
public static final String COLUMN_OBJ = "obj";
public static final String COLUMN_VTR = "vtr";
public static final String COLUMN_FKZ = "fkz";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_VNAME = "vname";
public static final String COLUMN_TEL = "tel";
public static final String COLUMN_FAX = "fax";
public static final String COLUMN_MOBIL = "mobil";
public static final String COLUMN_EMAIL = "email";
private static final String TAG = "ContactsDBAdapter";
private DBTools mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "hvkontakte.db";
private static final String DATABASE = "hvkontakte";
private static final String TABLE_NAME = DATABASE;
private static final int DATABASE_VERSION = 1;
private final Context mCtx;
private static final String DATABASE_CREATE =
"CREATE TABLE " + TABLE_NAME + "(" + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_TYPE + ", " + COLUMN_CLTYP + ", " + COLUMN_MDT + ", " + COLUMN_OBJ + ", "
+ COLUMN_VTR + ", " + COLUMN_FKZ + ", " + COLUMN_NAME + ", " + COLUMN_VNAME + ", "
+ COLUMN_TEL + ", " + COLUMN_FAX + ", " + COLUMN_MOBIL + ", " + COLUMN_EMAIL + ")";
private static class DBTools extends SQLiteOpenHelper{
public DBTools(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase database) {
Log.w(TAG, DATABASE_CREATE);
database.execSQL(DATABASE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {
database.execSQL("DROP TABLE IF EXISTS" + DATABASE);
onCreate(database);
}
}
public ContactsDBAdapter(Context ctx){
this.mCtx = ctx;
}
public ContactsDBAdapter open() throws SQLException{
mDbHelper = new DBTools(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close(){
if(mDbHelper != null){
mDbHelper.close();
}
}
public long createContact(String type, String cltyp, String mdt, String obj, String vtr,
String fkz, String name, String vname, String tel, String fax,
String mobil, String email) {
ContentValues initialValues = new ContentValues();
initialValues.put(COLUMN_TYPE, type);
initialValues.put(COLUMN_CLTYP, cltyp);
initialValues.put(COLUMN_MDT, mdt);
initialValues.put(COLUMN_OBJ, obj);
initialValues.put(COLUMN_VTR, vtr);
initialValues.put(COLUMN_FKZ, fkz);
initialValues.put(COLUMN_NAME, name);
initialValues.put(COLUMN_VNAME, vname);
initialValues.put(COLUMN_TEL, tel);
initialValues.put(COLUMN_FAX, fax);
initialValues.put(COLUMN_MOBIL, mobil);
initialValues.put(COLUMN_EMAIL, email);
return mDb.insert(TABLE_NAME, null, initialValues);
}
public boolean deleteAll() {
int doneDelete = 0;
doneDelete = mDb.delete(TABLE_NAME, null , null);
return doneDelete > 0;
}
public Cursor getAll() {
Cursor mCursor = mDb.query(TABLE_NAME, new String[] {COLUMN_ID,
COLUMN_TYPE, COLUMN_CLTYP, COLUMN_NAME, COLUMN_VNAME},
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public void insertSomeContacts(){
createContact("vtr","Tenant","1","82","1","2","Bennett","Tony","0911-123456","0911-123457","01577-12345678","info#email.com");
createContact("vtr","Owner","1","82","","","Smith","Brad","0911-1234567","0911-1234567","01577-84368365","info#email.com");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
//createContact("","","","","","","","","","","","");
}
}

work with SharedPreferences. Set a init boolean. if init is false insert the contacts -> set the init to true. after restarting do noting when init is true.
But this is maybe not the best solution for your usecase...

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Try removing c.close() and use startManagingCursor(c) (after creating the cursor) in your getData() method

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take all the values from database and store it in a string array

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